Composite photography



y 1949. B. c. HASKAN 2,200.35

COMPOSITE PHOTOGRAPHY Filed April 11, 1938 6 Shuts-Sheet l INVEN TOR.BYPOA/ C HA sm/v BY MW- A TTORNEY c HAsKaN COMPOSITE PHOTOGRAPHY FiledApril 11, 1938 ZEQQBSQ 6 Sheets-Sheet 3 B G. HAKIIN CQMPOSITEPHOTOGRAPHY Filetl April ll, 1938 INVENTOR. 15' Yea/v C max/1v ATTORNEYPIE. 4

May 14, 1940.

B. C. HASKIN COMPOS ITE PHOTOGRAPHY,

Filed April 11, 1938 6 Sheets-Sheet 5 INVEN TOR. BYPON C HAsK/N ATTORNEYPatented May 14, 1940 PATENT OFFICE 2,200,358 COMPOSITE PHOTOGRAPHYByron C. Haskin, Beverly to Warner Bros. Pictures, Inc.,

Hills, CaliL, asslgnor New York,

N. Y., a corporation of Delaware Application April 11,1938, Serial No.201.312

8 Claims.

This invention relates to composite photography and particularly to thattype wherein the images of a background component are projected on aprojection screen, and an object or set comprising the foregroundcomponent is photographed in front of the screen together with theprojected pictures of the background component.

In composite photography of the above type, the maximum size of thebackground image which may be projected on a translucent screen withsuiiicient amount of luminosity to permit photographing the same at amotion picture speed is determined icy several factors among which arethe ability of the film to resist heat, the amount of projection lightavailable, and the permissible amount of. magnification of the filmimages before the grain pattern of the film emulsion is noticeable.

When colored composite pictures of the above type are made anotherserious limitation is introduced. This is in part by the decreasedluminosity of the projected background images due either to filteringaction of colored films in the subtractive type of color projection orto the filtering action of color filters in front of the films inadditive type of color projectime. Furthermore, due to the necessarycolor filtering action of color films they require an irrcreaseci amountof actinic light for proper expo sure, thus necessitating a greaterbrilliancy of the projected background picture than is necessary forordinary black. and white photography. Also, since all commerciallysuccessful color photography processes at the present time require theuse of two or more light sensitive films in the color camera the amountof light available for each film is still further reduced. in the past,the above limitations have resulted the maximum dimension of coloredprojected background scenes being oi the order of about nine feet which,of course, greatly limits the permissible size of the foregroundcomponent being photographed loeiore the translucent screen.

In cases where the silver image is projected on the screen for compositephotography of the projected background type, Whether for black andwhite or color, the size of the projected background image is limitedlargely by the enlargement of the silver grain, that is, when themagnification of the background image exceeds a certain amount the grainpattern becomes apparent which causes the detail of the projected imageto be lost.

The object of the present invention is to remove to a substantial extentthe above mentioned limitations.

Method and means, including improved projector equipment, foraccomplishing the above and other objects of the invention will beapparent from the following specification read in conjunction with theaccompanying drawings wherein:

Fig. l is a plan view of a preferred form of apparatus, embodying thepresent invention, for producing composite motion pictures of thebackground projection type.

Fig. 2 is a front elevational view of the projector unit illustrated inFig. 1.

Fig. 3 is a sectional side elevational view taken substantially alongthe line Il3 of Fig. 2.

Fig. l is a sectional plan View through the support for the rearprojector lamp house and is taken along the line l-il of 3.

Fig. 5 is a fragmentary sectional view of the rear projector lamp houseadjustment and is taken along the line 5"?) of Fig.

Fig. 6? is a sectional View, with parts broken away, through the supportfor the projector unit and is taken along the line t-li of Fig. 3.

Fig. 7 is a transverse sectional view through the hearings forsupporting the projector unit for movement about a horizontal tilt axisand is taken along the line 'l-l of Fig. 6.

Fig. 8 is a transverse sectional pan adjustment of each projector alongthe line l ll oi Fig. 6.

Fig. 9 is a side View, partly in section, of one of the mirror mounts.

fig. ill is a rear view of the mirror mount illustrated in Fig. 9 and istaken in the direction of the arrow it of that figure.

Fig. ll is a transverse, sectional view through one of the objectivelens mounts and is taken along the line ll-l l of Fig.

Fig. 12 is a transverse, sectional View through one of the take-up reelmagazines and support therefor and is taken along the line l2 l2 oi Fig.6.

Fig. 13 is a fragmentary sectional view through the pan adjustment ofthe projector unit and is taken along the line BEL-l3 of Fig. 2.

Fig. 1c is a transverse, sectional view through the lamp house focusingmechanism for one of the projectors and is taken along the line 14-44 ofFig. 3. V

Fig. 15 isa front elevational form of projector unit.

Fig. 16 is a sectional side elevational view of the projector unitillustrated in Fig. 15 ;and is View of the and is taken view 01 anothertaken substantially along the line |6--|6 of that figure.

Fig. 17 is a sectional plan view through one of the mirror adjustmentsillustrated in the unit of Fig. 15 and is taken along the line |1--|1 ofthat figure.

Fig. 18 is a sectional view through the tilt adjustment for the unitillustrated in Fig. 16 and is taken along the line |8-|8 of that figure.

Referring to Figs. 1, 2 and 3 in particular, the apparatus comprisesgenerally a pair of opposed motion picture projectors l0 and I! havingtheir optical axes in alignment with each other. A third projector I2 issituated at right angles to both of the projectors ID and II and has theoptical axis thereof intersecting the optical axes of the opposedprojectors. Mirrors I3 and H in dividual to the projectors l0 and M,respectively, are provided to deflect the light beams therefrom in adirection substantially parallel to the 'light beam emitted by theprojector l2. These mirrors l3 and I4 are preferably so adjusted thatthe light beams deflected thereby intersect each other and the lightbeam from the projector |2 at a screen surface so as to produce, wheniden tical films are employed in the projectors IO, N and I2, a singlepicture with substantially three times the brilliancy of that obtainablefrom any one projector.

Fig. 1 shows an arrangement for producing composite motion pictures ofthe projected background type wherein the light beams l5, I6 and H fromthe projectors IO, M and I2, respectively, are superimposed in exactregistration upon one surface of a translucent screen I8. The projectorunit comprising the three projectors In, H and i2 is shown as beinghoused in a fireproof booth 1 having an enlarged opening 8 in one wallthereof to permit passage of the light beams l5, l6 and I1. A door 9 inanother wall of the booth 1 permits access to the interior thereof. Thebooth 1 may be movable if desired. A cinematographic camera H! at theopposite side of the screen I8 is provided to photograph the imagesprojected thereon. The foreground component 20 of the scene comprises asa matter of illustration a full size automobile situated on a stage 2|directly in front of the screen i8.

The camera i9 is coupled by suitable means, such as electricallyinterlocked synchronous motors, with the three projectors to insuresynchronous movement of the film advancing mechanisms for the camera andthe projectors. Elec trical couplings of this type are well known in theart and it is therefore deemed unnecesary to describe the same indetail.

The projectors In, H and i2 are identical with each other, eachcomprising generally a projector body 22, a film supply magazine 23thereon, and a motor 25 for driving the various film actuatingmechanisms therein. Objective lens tubes 26, 21 and 28 for theprojectors HI, I and I2, respectively, are supported independently ofthose projectors by three lens mounts 29 mounted on a casting 30. Theselenses are optically matched with each other to permit equalmagnification of the three projected images and to permit readyinterchangeability without correcting various adjustments. Casting 30 issecured on top of a T-shaped projector bed or base 3|, also forming asupport for the various projectors. Projector bed 3| is supported upon apedestal 32 for movement about a tilt axis passing through the centersof mirrors l3 and I4 which incidentally coincides with the alignedoptical axes of the projectors l0 and H through a hearing assembly,generally indicated at 33. The bed 3| has a depending saddle 34 (Figs. 6and '1) formed centrally thereof. Each leg 5 and 6 of the saddle 34 hasa pair of segmental bearing strips 35 and 36 secured to the innersurface thereof by screws 31. These bearing strips are each concentricwith the above described tilt axis and are received within arcuatebearing grooves 38 and 39 also concentric with the optical axes ofprojectors i0 and II. These grooves 38 and 39 are formed in a headcasting 40 secured by bolts 4| to the top of the pedestal 32. A lookscrew 42 extends through an arcuate slot 42, concentric with the slides35 and 36, in the leg 6 of the saddle formation 34 and is threaded inthe head casting 40 to clamp the projector bed 3| in different tiltedpositions. A worm gear segment 43, concentric with the above describedtilt axis is socured to the saddle leg 6 by bolts 44. Worm gear segment43 meshes with a worm 45 rotatably carried in bearings 46 and 41 (Fig.3) integrally formed on the head casting 40. A hand wheel 43 is providedto rotate the worm 45 to tilt the projector bed 3| and projectorsthereon.

Pedestal 32 has an annular bearing surface 49 formed on the bottomthereof which is received on a corresponding bearing surface 50 formedon a main base 5| to permit rotation of the pedestal 32 and bed 3| abouta vertical axis intersecting the intersection of the optical axes ofprojectors IO, U and I2. The base 5| is secured to the floor 52 of theprojector booth 1 by bolts 53. A tubular column 54 extending axially ofthe pedestal 32 is secured at its lower end within a hollow boss 55formed centrally in the base 5|. Column 54 extends through bearings 56and 51 supported within the pedestal 32 by radially extending flanges53. The upper end of the column 54 is threaded to receive retainer nuts59 to hold the pedestal 32 on the base 5| while permitting relativerotation therebetween.

Fig. 13 illustrates the adjustment for rotating the pedestal 32 on thebase 5|. This adjustment comprises a worm gear segment 6| suitablysecured by bolts (not shown) on a flange 62 formed integrally with thebase of the pedestal 32. The worm gear segment 6| is concentric with theaxis of rotation of the pedestal 32 and meshes with a worm 63 rotatablysupported in spaced bearings 64 and. 65 (Fig. 2) suitably secured to thebase 5 I.

A hand wheel 66 is provided to rotate the worm 63. A locking device isprovided for locking pedestal 32 in any desired position and comprises astud 61 suitably anchored in the base 5|. Stud 61 extends upwardlythrough an arcuate slot 61' formed co-extensively through both the boss62 and worm gear segment 6|. Slot 51' is formed concentric with the axisof rotation of pedestal 32. The upper end of stud 61 is threaded toreceive a clamp nut 63 for the purpose of locking the pedestal 32 on thebase 5|.

Referring now to Fig. 11 the objective lens mount 29 for each of theobjective lenses of the three projectors comprises a bracket 59 rigidlysecured to the casting 30. The upper end of the bracket 69 is formedinto a semi-circular lens receiving surface to receive the lower half ofa sleeve 1|) carrying the lens tube in which the various elements of theobjective lens are mounted. A semi-circular cover 1| is hinged at 1| tothe bracket 69 and is adapted to clamp the sleeve 10 and its lens tubein fixed position by means of a clamp screw 12. Screw 12 is pivotallysecured at one end thereof to a pin 13 extending between a pair ofspaced lugs 14 formed integrally with the bracket 69. A nut 15 threadedon the upper end-of the screw 12 is adapted to bear against a pair ofspaced lugs 76 on the cover II thus holding the cover in a clampedposition. A key 17 carried by the bracket 69 and projecting into thesemi-circular groove formed in the bracket 69 is provided to engage acorresponding notch in the sleeve 70 to facilitate correct positioningof the objective lens (Fig. 6).

As will be noted in Fig. 6 the objective lens tube 2'! carrying theobjective lens of the projector I! extends freely within an aperture 19formed in the front wall of the projector to permit projector II to bemoved relatively to the fixed sleeve 16 for focusing purposes, withoutlight leakage.

The mirrors I3 and I4 are preferably of the trout surface type such asobtained by employing highly polished Stellite plates and are supportedin adjustable mounts at El. The'mount for mirror It is illustrated inFigs. and 10. A triangular shaped lug 82 integrally termed on the rearof mirror I3 carrise a transversely extending bearing pin 33 locatedsubstantially centrally of the mirror. A pair of flanges 8t and 8tformed on an adjustable member 95 saddles the lug 82 and forms bearingsfor the pin 83. A worm gear segment 36, concentric with the bearing pin83 and formed on the lug 82, meshes with a worm 87 rotatably supportedat either end thereof in bearings 88 and 89' formed in the member 85. Aknurled knob 39 is provided to rotate the worm ill to tilt the mirrorabout pin 83. Member has a cone shaped hollow bearing surface on thebottom thereof which fits over a frustro-conical bearing projection 91provided on the upper surface of casting 30. Bearing St has the axisthereof passing centrally through the plane of the mirror surface of themirror I3. A bolt 92 is provided to retain the member 85 on the bearingSI while permitting rotation of member 85. Worm gear teeth 93 are formedaround the base of the member 85 and are engaged by a worm Q4 rotatablycarried in bearings 55 and 96 projecting from the casting 3B. A knurledknob W is 1 provided to permit rotation of the member 85 about avertical axis.

Each of the three arms of the T-shaped bed 3:! has a dovetailedguideway, IIlIl 6 and d) extending longitudinally thereon to slidablyreceive a slide 1M. Slide llll has a depending projection I02 integrallyformed thereon which extends through an elongated slot its in the bed BIand has threaded therethrough a screw Wt. Screw I04 is journalled ateither end thereof in bearings I05 and I06 depending from the base 3i. Abevel gear I07 secured on the screw ltd meshes with a second bevel gearI so carried on a shaft I09 journalled in bearings Hit and lit dependingfrom bed 39. A hand wheel M2 on the shaft I09 permits manual focusingadjustment of the projector.

Each projector is adjustable about a vertical axis passing through thecenter of the plane of the emulsion surface of the film in the film gatelid (Fig. 6) thereof to compensate for any possible keystone efiect ofthe projected images therefrom. A pad I I 4 secured to the bottom ofeach projector by screws H4 has a vertical pin H5 journalled therein andsecured to the slide IBI. Pin 5 is situated with the axis thereofgenerally indicated passing centrally through the plane of the film F inthe film gate H3 to permit movement of the projector therearound. Theprojector is movable about the pin 5 through an adjustment generallyindicated at IIG (Fig. 8). This adjustment comprises a transverselyextending screw II'I threaded within a projection H8 extending upwardlyfrom the slide IIH. Screw II! abuts at either end thereof against a pairof spaced lugs IL! and I20 integrally formed on the projector pad I. Aturret I2I secured on the screw II! is provided to permit manualrotation of the screw ill for adjustment of the projector about the pinH5. Clamp screws I22 and H3 extend through elongated slots I24 and I25,respectively, in the pad I I4 and are threaded in slide II to lock thepad H4 onto the slide IIiI. Slots I24 and 625 are formed concentric withpin .l I5.

Referring now to Figs. 6 and 12 the take-up reel I25 of each projectoris supported by the bed 3I independently of its respective projector.

he reel I25 is removably keyed on a spindle I26 journalled in a bearingI2? formed in a take-up magazine 28. Magazine I28 is supported from theunder surface of a projection of the bed 3| by a bracket I 29. Reel I25is driven by a pulley l3Il on shaft lit, deriving its rotation from apulley I3 (Fig. 2) through a continuous flexible belt M2. The pulley I3Iis suitably connected in the usual manner to the film driving mechanismin the projector.

The film. F enters the take-up magazine I28 through a fire trapcomprising two pairs of wringer or guide rollers E33, I33, I3 2 and I34.The upper pair of rollers H3 and E33 are rotatably supported on pinscarried on a bracket I35 (Fig. 12) mounted on the bedBl. The lowerrollers I34 and I34 The film is drawn through the picture gate H3 ectorby means of a pull down mechanism generally indicated at I31 (Fig. 6).dovm mechanism it? is preferably of the type employing pilot or registerpins to permit ac curate and steady registration of the film F while itis intermittently held stationary in the film gate From the pull downmechanism #32 the him is passed around a hold back sprocket ltd, over aguide roller m9, and thence between fire trap. Roller l39 is rotatablymounted in the body of the projector and extends through an opening I M)in the rear wall MI oi the projector thus guiding the film F from theprojector to its take-up magazine in all focused positions thereof. Achannel shaped cover member M2 is provided to protect the film passingbetween the roller N9 and the magazine E28. Cover I42 is pivoted on apin I 43 projecting from a suitable bracket (not shown) on the base 3iand is adapted to be swung outward to permit threading or inspection ofthe film. A door 245 hinged at 246 to the magazine I28 permits access tothe take-up reel I25.

An are light (not shown) is supported in a conventional type of lamphouse I64 (Fig. 2) for illuminating the film in projector HI to projectan image thereof to the screen surface. Lamp house I is adjustablysupported on a downwardly inclined arm I45 secured intermediate itslength to a bracket I46 which, in turn, is se cured to the side of thepedestal 32. Arm I45 is II also supported by track I59 as describedlater. An adjustment generally indicated at I41 is provided to move thelamp house I44 longitudinally thereof to correctly position the same fordifferent focusing positions of the projector I0. This adjustment It?comprises bevelled guide strips I48 and I49 (Fig. 14) secured alongeither side of the lamp house by screws 858. A correspondingly bevelledguide member I5I fitting the guides I48 and I49 is suitably secured ontop of the arm I45 and has a projection I52 depending therefrom tothreadably receive an adjusting screw I53. Screw I53 is rotatablymounted in a projection I54 depending from the lamp house I44 and isprevented from longitudinal movement relative therewith by suitablecollars I55 thereon situated on either side of the projection I54. Ahandle I56 on the end of screw I53 is provided to permit longitudinalmanual adjustment of the lamp house I44.

Arm I45 has a hollow skirt I51 formed at the bottom thereof in which isrotatably mounted a pair of rollers, one of which is shown at I58.Rollers I58 ride along a track I59 integrally formed on the main base 5ito assist in supporting the lamp house M4. Track I59 extends concentricwith the axis of rotation of pedestal 32.

The are light for the projector II is provided in a lamp house I68,which is supported for longitudinal adjustment as generally indicated atI6i, the same as the longitudinal adjustment for the lamp house M4. Lamphouse I60 is supported on the top of an arm I62 secured intermediate itslength to a bracket I63 which in turn is secured to the side of pedestal32, opposite the point where bracket I 46 is secured thereto. Arm I62also has rollers, one of which is shown at I65, rotatably mounted in anenlarged skirt I66 therein for movement along the circular track H59.

It is to be noted that the lamp houses I44 and I60, although movableabout a vertical axis through the center of pedestal 32 in fixedrelation with their respective projectors, are not rotatable about ahorizontal axis with those projectors when hand wheel 48 is manipulatedto tilt the projectors.

A lamp house I61, similar to those of I44 and I69, carrying an are lightis provided for the projector I2. Lamp house I61 is supported on acurved arm I68, concentric with the aligned optical axes of theprojectors I and II, through longitudinal adjustment I69 similar to thatprovided for lamp houses I44 and I60. Arm I68 (Figs. 3, 4 and issubstantially square in cross section and has raised bearing portions Iat either corner thereof. Arm I68 is slidable within a curved bearingmember I1I. Member I1I comprises in cross section a lJ-shaped castingI19 having a cover plate I12 secured thereto by screws I13 to enclosethe arm I68. Bearing member I1I is supported in part by a bracket I14secured thereto and to the pedestal 32 intermediate the points wherebrackets I46 and I63 are connected. Member I1I is also supported from atrack I by a tubular framework I16 on the lower end of which is mounteda pair of rollers I11 and I18 movable along the track I15. Track I15 isconcentric with track I59 and may be inset in the floor as shown in Fig.3. Framework I16 comprises a pair of spaced vertically extending tubularposts 241 and 24B attached at their upper ends to either side of thebearing member Ill and terminating at their lower ends in a hollow skirt249 in which are mounted the rollers I11 and I18.

Means are provided to move the lamp house I61 in a curved path to alignthe same with the projector I2 for different positions thereof about thehorizontal tilt axis of the projector unit. To accomplish this a curvedgear rack I80 is integrally formed along a portion of the arm I68. Agear I8I meshes with the rack I88 and is carried on an axle I82journaled within bearings I83 and I84 formed in a gear casing I85. Gearcasing I85 is secured to the outer flange I86 oi the bearing member I1Iby bolts I81 and encloses an aperture I86 formed in the flange I86 topermit the gear I8I to mesh with rack I80. A worm I88 meshes with thegear I8i and has the shaft I89 thereof journalled within bearings I90and I9I also formed in the gear casing I85. A hand wheel I92 is providedon the shaft I89 to permit manual rotation of the worm I88 to adjust thelamp house 16*! about the horizontal tilt axis of the projector unit.

In operation, the various elements of the projector apparatus areadjusted as follows: The rear projector I2 is first illuminated toproject the beam of light I1 therefrom onto the screen I8. The projectorbase ill is then panned and tilted by means of the hand wheels 66 and48, respectively, until the beam I1 is centrally located on the screenI8. This panning movement of base 3I has served to move all the lampswith their respective projectors as the projectors and their lamp housesare moved about a vertical axis when pedestal 32 is rotated by handwheel 66. However, hand wheel 48 tilts all the projector-s withouttilting any of their respective lamp houses and lamp house I61 is theonly one which must be given a corrected tilt adjustment (by hand wheelI92) when the projectors are tilted. With the construction shown, thereis no necessity or a tilt adjustment of lamp houses I44 and I60 when allthe projectors are tilted, as the tilt movement is about an axis passingthrough the optical axis of lamp houses I44, I60 and their projectors.The hand wheel I92 is rotated until the lamp house I61 assumes thecorrect position relative to the projector I2, that is, until the arelight therein is aligned with the optical axis of the objective lens ofprojector I2. The arcs for the projectors I0 and II are then lit toproject the beams I5 and I6, respectively therefrom, onto the screen I8.The mirrors I3 and I4 are then adjusted roughly to register the twobeams I5 and I6 with the beam I1 from projector I2.

If the background scene is to be projected in black and white, threeidentical positive prints from the same negative of the background sceneare prepared and are threaded in the three projectors. However, if thebackground scene is to be projected in color according to the additiveprocess, three positive prints are respectively prepared from threecolor separation negatives of different color aspects of the backgroundscene (assuming a three color process is employed) and are threaded inthe three projectors. Again, if the background is to be projected incolor according to the substractive process, three identical and naturalcolored prints of the same color negative or set of color negatives ofthe background scene are prepared and threaded in the three projectors.The three positive prints regardless of how they are obtained, areprovided with synchronized starting marks by which they may all bestarted in the same relative positions in the projectors.

In any of the above cases, after the three projectors are properlythreaded, they are successively illuminated and focused by the handwheels H2 until the projected image from each is sharp on the screen I8.In the final adjustment all three projectors are illuminated and themirrors I3 and I4 are minutely adjusted by means of the knobs 89 and 91(Figs. 9 and 10) to obtain exact registration of the three light beamsI5, I8 and IT on the screen I8.

In making a composite background type picture as illustrated in Fig. 1,the motor of the camera I9 is interlocked, as described hereinbefore,with the projector motors 25 to photograph the foreground 20 with theprojected background picture appearing on the screen I8. Thiscinematographic operation may, of course, be performed whilesimultaneously recording the dialogue or other sounds produced by actorsin or on the foreground set 29.

Referring now to Figs. 15 to 18, inclusive, I will now describe analternative form. of projecting apparatus embodying the presentinvention. Three projectors I93, I94 and I95 are mounted upon a T-shapedbed or base I98. These projectors are mounted in a manner similar tothat of projectors H), II and I2, the projectors I93 and I95 being inopposed axial alignment with each other. The projector I94 is arrangedat right angles to the projectors I93 and E95 and has its optical axisintersecting their optical axes. The mount for each projector comprisesan inverted U-shaped base I97 (Fig. 16) suitably secured on therespective arm of the bed. I96. The respective projector rests upon theupper surface of the base I97. A clamp screw I98 extends up;- wardlythrough an elongated slot I99 in the base I9? and is threadably securedin the bottom of the projector to lock the same in various positions onthe base Hit.

The take-up magazine 209 for each projector has a base Elli (Fig. 15)formed thereon which is adapted to be secured by bolts (not shown) tothe under surface of the bed I96. Slots 292 formed co-extensivelythrough the projector base Hi, the bed Hit, and the magazine base 20Iare provided to permit the film F to pass from the projector to the takeup reel (not shown) within the film magazine 2%. Mirrors 28 3 and; 2535are provided to deflect the light beams from the projectors and i955,respectively, in directions substantially parallel to that of the lightbeam from the projector 59%. Each of these mirrors is supported by anadjustable mount 296 (Hg. 17) from the bed Mount 296 comprises a base2911 suitably secured to the upper surface of the bed A standard 298extending upwardly from the base Zli'i carries an annular memberthereon. Member 299 has threaded therethrough in quadrilateralrelationship four adjusting screws Elli. Each of these screws 2I0 has aball shaped formation 2H at the forward end thereof which is receivedwithin a socket 2I2 formed in the rear of the respective mirror (205).Screws 2H3 permit adjustment of the mirrors into various positions.

Lamp houses M3, 2 and 2I5 are provided for the projectors I93, I94 andI95, respectively. Each of the lamp houses rests upon one arm of theT-shaped bed E96. Clamp screws 2| 6 and 2II (Fig. 16) extend upwardlythrough elongated slots 2!!! and 2I9, respectively, in each arm of thebed I95 and are threadably secured in each lamp indicated at 220, isprovided house to clamp the same in different positions on the base I96.A supporting framework, generally to adjustably support the bed I98 indiflferent positions. Framework 220 comprises a pair of spaced verticalposts HI and 222 having cross pieces 223 and 224, respectively, uponwhich the outer ends of the arms 225 and 226, respectively, of the bedI96 rest. The third arm 221 of bed I96 rests at its outer end upon across piece 228 supported by a jack 229. Jack 229 is supported on ablock 239. Cross piece 228 is vertically reciprocatable along verticalguides 23I and 232 (Fig. 18), secured to the block 230, by the jack 229to tilt the projectors about a horizontal axis parallel with the opticalaxes of the two opposed projectors I93 and I95. A vertical center post233 supports the bed I98 at the juncture of the arms 225, 226 and 221. Abolt 234 passing through the base I 96 and threaded in the post 233forms a pivot for guiding the projector unit in a horizontal directionabout the intersection of the optical axes of the three projectors I93,we and I95.

A single motor 2-36 is provided to drive the three projectors i93, I94and I95 in synchronism. Motor 236 drives the film advancing mechanism ofthe projector I95 through a pair of co-extensive shaft sections 231 and238 having formed therebetween a telescoping coupling 239. Universaljoints 24B and 25! adjacent the opposite ends of the shaft sections 237and 298 permit relative movement between the motor 236 and projectorunit while maintaining a driving connection therebetween. Shafts 243 and2 interconnecting the 'film advancing mechanism of projector I95 withthat of the other we projectors I 94 and I93 comprise a synchronousdrive for the three projectors.

When producing colored composite pictures using the additive type ofprojected colored background, three positive prints having diiferentcolor aspects of the same background scene are placed in the threeprojectors. be either dyed in accordance with their respective coloraspects or they may be ordinary black and white prints, in which case,filters of colors corresponding to the color aspects of the prints areprovided in front of the respective projectors so as to produce threedifferently colored image beams. These image beams when united insuperposition on the screen render the projected background image innatural colors.

Colored composite pictures may also be produced by employing thesubtractive type of projected colored background such as is obtained byusing the well known Technicolor type of color films for projection. Inthis case three identical positive prints, each having been prepared innatural colors from the same set of negative films of the background arethreaded in the three projectors. Each of these films is preferablyobtained by successively imbibing dyes onto a substantially blank filmfrom different negatives These prints may having different color aspectsof the same scene.

The negatives have previously been formed into matrices by mordantingand dyeing the images thereon with dyes of colors complementary to thecolor aspects of the negatives according to the Technicolor process.This subtractive type of projection has been found to be superior to theadditive type of projection due to fine reduced color filtering effectof the projected light beams as well as the reduction of grain and tothe fact that the silver grain image, if any, in Technicolor prints ismuch fainter than the silver ISIS grain image in films used in theadditive process, thus permitting more light to pass through the films.

Various color effects such as a correction of color balance or anincrease in the intensity of a certain color component in projecting acolored background may be obtained by employing in the arc lights forthe various projectors special carbon electrodes which emit apreponderance of one color or another.

The use of the invention in conjunction with the projection of ordinaryblack and white silver image films or dyed silver image films results ina large reduction of projected silver grain pattern. This pattern is dueto the clustering of the minute silver grains in the film emulsions.Since the arrangement of the silver grain pattern in different films ordifferent portions of the same film is, of course, different, thesuperposition of several identical and registered projected film imageson a screen will result in the projected minute voids or openings causedby the clustering of grains in one film emulsion being filled by theprojected images of the minute clustered grains themselves in anotherfilm emulsion.

Due to the above noted reduction of grain pattern the details andclearness of the projected background picture will be materiallyincreased. Also due to the reduction of the minute voids in theprojected pictures which are caused by the clustering of silver grainsin the film emulsion, the shadows or darkened portions of the projectedpictures will be rendered darker resulting in a greater contrast valuebetween highlights and shadows. This increase in contrast value reducesthe washed-out appearance noted in projected background type ofcomposite pictures.

A further feature of the invention resides in the fact that the increasein luminosity or brilliancy of the projected background component of acomposite scene permits the foreground component to be illuminated to agreater extent while preserving the lighting balance between thebackground and foreground components. Since the maximum exposure time ofthe camera is limited due to the fact that cinematographic camerasoperated in conjunction with sound recording apparatus aremaintained ata standard speed, i. e. twenty-four frames per second, the above featurepermits smaller lens openings to be employed to increase the depth offocus of the cinematographic camera.

In the preferred form illustrated in Figs. 1 to 14, inclusive, theprovision for tilting the projector unit about an axis passing throughthe centers of the angularly positioned mirrors .has the advantage thatthe lengths of the optical paths between the films in the variousprojectors and the projection screen all remain the same for differenttilted positions of the projector unit, and therefore the registrationof the three projected images from the three projectors remainsundisturbed. This feature remains the same regardless of the relativepositions of the projectors. That is, if the projectors l0 and H werepositioned midway between their illustrated positions and the projectorl2 (or in any other position) while the mirrors l3 and M were adjustedto register the various superimposed projected images, this registrationof the various images would remain undisturbed provided that theprojector unit was tilted about the axis passing through the centers ofthe mirrors l3 and 14.

The importance of the above feature is recognized by the fact that amovement of the order of one inch of the projector unit toward or awayfrom the projection screen will result in the registration of thesuperimposed projected images from the three projectors becomingnoticeably disturbed.

In order to correctly adjust the position of the lamp house I61 forvarious tilted positions of the projector l2 on bed 3|, correspondingscales may be provided on the leg 6 of saddle 34 and on the curved armI68 supporting lamp house I51 to bring these members into alignment.

Although the invention has been described in reference to and isparticularly adapted to the production of cinematographic compositepictures, it is to be understood that it may be employed in connectionwith the production of still composite pictures, or to the production ofcinematographic composite pictures wherein still pictures are projectedupon a background projection screen. It is further contemplated that theprojection apparatus may be employed to project pictures on a screen foraudience purposes. I intend, therefore, to be limited only to the extentindicated by the scope of the following claims.

I claim:

1. Projecting apparatus comprising three projectors directed toward acommon point, two of said projectors being axially aligned with eachother and each arranged at 90" to the axis of the third projector, lightdeflectors for deflecting the light beams from said axially alignedprojectors in directions substantially parallel to the light beam ofsaid third projector, an objective lens for each of said projectors,means for supporting said lenses in fixed relation to each other, andmeans for moving said projectors along their respective optical axes forfocusing.

2. Projecting apparatus comprising three picture projectors directedtoward a common point, light sources for said projectors two of saidprojectors having co-axially aligned optical axes, and each of said axesbeing arranged at 90 to the optical axis of the third projector, lightdeflectors for deflecting the light beams from said co-axially alignedprojectors in directions substantially parallel to the light beam ofsaid third projector, means for moving said projectors about ahorizontal axis independently of said light sources, and means formoving said projectors and light sources together about a vertical axis.

3. Projecting apparatus according to claim 2 comprising means for movingthe light source for said third projector about said horizontal axis.

4. A projecting apparatus comprising a T- shaped base member havingthree arms, a picture projector on each arm of said base member anddirected toward the juncture of said arms, and mirrors on said basemember for deflecting the projected light beams from the opposed ones ofsaid projectors substantially parallel to the projected light beam fromthe remaining projector, and a tilt support beneath said base member fortilting the same about the optical axis of said opposed projectors.

5. A projecting apparatus comprising a T- shaped base member havingthree arms, a picture projector having a film gate and a film movementon each arm of said base member and directed toward the juncture of saidarms, objective lenses for said projectors, means on said base memberfor supporting said objective lenses in fixed relation to each Other,mirrors on said base member individual to each of the opposed ones ofsaid projectors for deflecting the projected light beam therefrom tointersect the light beam from the remaining projector at a remote point,and means for moving each of said projectors in an axial directionrelative to its objective lens for focusing.

6. Projecting apparatus comprising a picture projector having a filmgate, a film movement and an objective lens, supporting means for saidprojector with its film gate and film movement and forming an arcuatebearing surface concentric with a point on the optical axis of saidprojector in front of the objective lens thereof, a supporting member,means on said supporting member forming an arcuate bearing surfacecorresponding to and supporting said first mentioned bearing surface, alamp house for saidv projector, supporting means for said lamp houseforming an arcuate bearing surface concentric,

with said point and second means on said supporting member forming anarcuate bearing surface corresponding to and supporting said lastmentioned bearing surface.

7. Apparatus for projecting cinematographic pictures comprising thecombination of a motion picture projector on each side of a third motionpicture projector, the optical axes of'all three of said projectorsbeing arranged in acommon. plane, said third projector comprising means{gr projecting a motion picture on a remote screen, means associatedwith each of said side projectors for simultaneously reflecting thebeams from said side projectors at points outside of the beam from saidthird projector, said deflecting means and said projectors being sopositioned that the length of the optical path from each of said threeprojectors to said screen is substantially the same, means for adjustingsaid deflecting means for bringing the beams from said side projectorsinto registration with each other and with the beam from said thirdprojector at said screen, and means for rotating said three projectorsas a unit around an axis passing through the locus of said deflectingmeans for said side projectors to suitably position the projectedpictures as a, unit on said screen.

8. A triple head comprising two opposed projectors and a third projectortherebetween, said projectors being directed towards a common point, amirror for each of said opposed projectors and arrangedat one side ofthe optical axis of said third projector, a common support for saidprojectors, means for moving said support about a vertical axis throughsaid common point, means for moving said support about. a horizontalaxis coinciding with the aligned optical axes of said opposedprojectors; each of said projectors comprising a lens tube fixed to saidsupport, a takeup magazine fixed to said support, and a projector casingcarried by said support and associated with and movable between saidlens tube and said take-up magazine; a lamp house for each of saidprojector casings, and meansadjustably supporting each ofsaid lamphouses independentlyof said support.

BYRON c. HASKIN.

